JPS6179749A - Permanent magnet alloy - Google Patents

Abstract

PURPOSE:To obtain a permanent magnet alloy having improved maximum energy product as well as increased coercive force, by substituting a specific amount of at least one kind among Ti, Hf, Zr, and Nb for a part of Fe, in the alloy consisting of specific percentage of rare earth elements, B and Fe. CONSTITUTION:At least one kind among Ti, Hf, Zr, and Nb is added to the R-B-Fe permanent magnet alloy having a composition consisting of 8-30atomic% R (at least one kind among the rare earth element s including Y), 2-28atomic% B, and the balance Fe, as substitute for a part of Fe, by <=15atomic%.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to the improvement of a rare earth-iron-boron permanent magnet alloy, which can be used as one of the key materials for various industrial and consumer electrical and electronic devices. Used.

Specifically, it can be used in a wide range of fields, including small audio speakers, computer peripheral terminal equipment, various small motors, and stepping motors for crystal clocks.

[Prior Art] JP-A-59-46008 discloses the composition and manufacturing method of a rare earth iron magnet containing B.

[Problem to be solved by the invention] Conventional R-B-F'e magnets have high magnetic properties at temperatures below room temperature. B was added for the purpose of obtaining a compound, and high performance was achieved. However, compared to known samarium cobalt magnets, A7t has the disadvantage of having a smaller coercive force and greater variation, which is a major obstacle to stable production. there were.

[Means for solving problems]

In order to solve all of the above problems, the present invention aims to solve all of the above problems.
Considering that one of the effective methods for improving coercive force in boron-iron ternary compounds is to use additive elements,
Using the neodymium-poron-iron system as a starting point, we conducted experiments and studies by adding numerous elements. The result is 7'CTi as shown in the claims.

It was found that the addition of Zr, Hf and N'b was a means to solve the problem.

〔Example〕

In the following, the present invention will be explained according to examples.Ti, Zr, Hf, and Nt), which are elements that have been found to be effective in improving coercive force in preliminary experiments, are selected as additive elements, and are shown in Table 1. All alloys with the composition shown were fabricated.

Table 1 Alloy Composition The alloy was produced by casting into a water-cooled copper mold using a high frequency melting furnace in an argon gas atmosphere.

The ingot is crushed in an argon gas atmosphere using a show crusher until the particle size becomes 111111 or less.
Next, use a disk mill around the entire circumference to grind the material to about 100 microns. Further, the obtained powder was placed in a stainless steel container for a vibrating ball mill, and the powder was crushed into 2"L balls and toluene was completely enclosed as a coolant, and the vibrating mill was pulverized until the average particle size was about 3 microns. Next, the thus obtained NFC fine powder i 10 KOe is oriented in a magnetic field, and compression molding is performed in a direction perpendicular to the orientation direction at a pressure of 2 tons/- to produce a 15 m square compact.

After this, the molded body was heated at 1°C at 80°C in an argon atmosphere.

Sintering was performed for 1 mn, and immediately after sintering, it was rapidly cooled in a cooling chamber.

Further, the sintered body was heated and held at 650° C. for 1 hour in an argon gas atmosphere, and after being heated and held, it was rapidly cooled in a cooling chamber. Measurement of magnetic properties is carried out from block 41. A sample of φX10 mm was cut out, a demagnetization curve mk was determined using a 4πX-H horizontal coaxial compensation coil, and each measured value was read. Second
The table shows the results.

Table 2 Magnetic property measurement results Figure 1 shows that when all of Ti, Hf, Zr and Ml are added, the amount of addition is less than that of IHc and shows no influence. As is clear from the figure, the addition of these fourth elements is different from conventional N
It can be seen that IHc is clearly improved compared to the d-B-Fe ternary alloy. In particular, the effect of Zr addition is remarkable (conventional 6KO
Compared to e, the addition of 10Az% resulted in a total of 12KOe.
It has also improved. As a result, the maximum magnetic energy MGO energy product, which is the most important property required for a permanent magnet, has been dramatically improved from the conventional 24 to 2a3. Figure 2 shows the conventional N
The highest magnetic properties are obtained with d15 Bg Feyy alloy and n7' (Nd, B, Fe6. Zr
The I-H curve of alloy No. 1 (1) shows that although Br slightly decreases due to the addition of Zr, IHc becomes thicker (it is noticeable that the squareness of the knee H curve is improved).

FIG. 5 shows the influence of the amount added on the maximum magnetic energy product when all the fourth elements are added. , according to the figure, the maximum magnetic energy product is Ti.

Hf, Zr and Nb additions are also 5-10 At% O
However, if it exceeds 15 At% t-, the properties will be lower than those of conventional products without additives.

This is due to the decrease in Fe element with high saturation magnetism due to the addition of the fourth element, and the decrease in Br and 15A
When the addition amount is less than t%, the squareness of the I-H curve is improved, but when the addition exceeds 15 At%, the squareness ratio deteriorates due to fc and 'fc. That is, if it is not preferable to add the fourth element, and considering practicality, the upper limit is considered to be within 15 At% of each element.

Although the present invention has been described above based on Examples, the present invention is not limited to these Examples and described aspects. That is, in the example, the base alloy composition k Nd+s”a
Fe? ? However, the effect of adding the fourth element in the present invention is not only due to this composition, but also in the above-mentioned JP-A-59-4.
The composition described in No. 6008 also has similar effects.

Furthermore, although each of the fourth elements was added individually, it can be easily inferred that the combined addition of one or more elements would have the same effect.

[Effects of the Invention] As described above, the present invention uses Ti as a fourth element in an R-B-IFe alloy containing Nd, Pr, etc. as main components.

By adding Hf, Zr, and Nb alone or in combination, it is possible to increase the coercive force and improve the squareness of the I-H curve, which is the most important characteristic for permanent magnets. With an improvement in the maximum energy product,
Its industrial significance is great.

[Brief explanation of the drawing]

Figure 1 is Nd1llB8Fe? ? -XMX (However, M
= Ti, Hf. Figure 2 shows the influence of X on IHc in Zr and N1)) series alloys.
The following graph compares the I-H curves of the 0 alloy and the conventional alloy. Figure 6 shows the relationship between the amount of added element MOX and the maximum energy product (B H) mx in Nd, 5B, Fe7y-Mx alloys. This is a graph. that's all

Claims (1)

[Claims] In an alloy with a composition consisting of 8 to 30% R (at least one rare earth element including Y) in atomic percentage, 2 to 28% B, and the balance Fe, part of the Fe is added to 15% or less Ti, H
An alloy for permanent magnets, characterized in that it contains at least one of f, Zr and Nb.